So, having caught up with the entire series (gulp), I think I can give the comparative impressions of each arc, even by the weird baseline of Kirov as a whole:
Books 1-3: This is the most coherent and understandable arc in the series. It's also full of contrivances to have the ship fight at all
and to threaten it with WWII technology. Ends on an actually good conclusion, but is the clunkiest in terms of action.
Books 4-8: A jumbled mess that's more about introducing potential plotlines than actually resolving anything-by now the cash cow is there. The pacing is a little better than the mega-arc that follows, but the action is a lot worse (going to full wargame LP actually made the battles somewhat
better).
Books 9-40: The big arc of WW2. Essentially the median of the series. What more can I really say?
Books 41-48: A contemporary WW3, and probably the worst arc in the series because it's the most mundane.
Books 49-53: Another "contemporary" WW3, but significantly better than the previous one because, unlike the last one, it takes full advantage of the alternate history and goofy elements (one of the best scenes is where the ship timeshifts into a place inhabited entirely by hostile drones and fights them).